Class PinchToZoomGesture

java.lang.Object
com.jogamp.newt.event.PinchToZoomGesture
All Implemented Interfaces:
GestureHandler

public class PinchToZoomGesture extends Object implements GestureHandler
2 pointer zoom, a.k.a. pinch to zoom, gesture handler processing MouseEvents while producing PinchToZoomGesture.ZoomEvents if gesture is completed.

Zoom value lies within [0..2], with 1 as 1:1.

   - choosing the smallest surface edge (width/height -> x/y)
   - tolerating other fingers to be pressed and hence user to add functionality (scale, ..)
 
  • Field Details

    • DEBUG

      public static final boolean DEBUG
  • Constructor Details

    • PinchToZoomGesture

      public PinchToZoomGesture(NativeSurface surface, boolean allowMorePointer)
      Parameters:
      surface - the NativeSurface, which size is used to compute the relative zoom factor
      allowMorePointer - if false, allow only 2 pressed pointers (safe and recommended), otherwise accept other pointer to be pressed.
  • Method Details

    • toString

      public String toString()
      Overrides:
      toString in class Object
    • clear

      public void clear(boolean clearStarted)
      Description copied from interface: GestureHandler
      Clears state of handler, i.e. resets all states incl. previous detected gesture.
      Specified by:
      clear in interface GestureHandler
      Parameters:
      clearStarted - if true, also clears started state, otherwise stay within gesture - if appropriate. Staying within a gesture allows fluent continuous gesture sequence, e.g. for scrolling.
    • isWithinGesture

      public boolean isWithinGesture()
      Description copied from interface: GestureHandler
      Returns true if within a gesture as detected by a previous GestureHandler.process(InputEvent) command, which has not been cleared. Otherwise returns false.
      Specified by:
      isWithinGesture in interface GestureHandler
    • hasGesture

      public boolean hasGesture()
      Description copied from interface: GestureHandler
      Returns true if a previous GestureHandler.process(InputEvent) command produced a gesture, which has not been cleared. Otherwise returns false.
      Specified by:
      hasGesture in interface GestureHandler
    • getGestureEvent

      public InputEvent getGestureEvent()
      Description copied from interface: GestureHandler
      Returns the corresponding InputEvent for the gesture as detected by a previous GestureHandler.process(InputEvent), which has not been cleared. Otherwise returns null.

      Only implemented for gestures mapping to InputEvents.

      Specified by:
      getGestureEvent in interface GestureHandler
    • getZoom

      public final float getZoom()
      Zoom value lies within [0..2], with 1 as 1:1.
    • setZoom

      public final void setZoom(float zoom)
      Set zoom value within [0..2], with 1 as 1:1.
    • process

      public boolean process(InputEvent in)
      Description copied from interface: GestureHandler
      Process the given InputEvent and returns true if it produced the gesture. Otherwise returns false.

      If a gesture was already detected previously and has not been cleared, method does not process the event and returns true.

      Besides validation of the event's details, the handler may also validate the InputEvent.InputClass and/or InputEvent.InputType.

      Specified by:
      process in interface GestureHandler